The invention relates to a tool clamping system having a rotationally drivable tool holder for clamping a tool.
Tool clamping systems of this type have been known for decades and are used in many ways when machining workpieces.
For some years, it has been required in some machining centers with rotating tools, in addition to the conventional cutting tools, to also provide for measurement-based applications or monitoring operations of the tool. These are generally applications in which a measurement system, usually based on electromechanical principles, is mounted on a spindle interface. On the one hand the connection and guidance is to be ensured by the machine kinematics, and on the other hand the sensing of the measured values and transfer thereof to the controller are to be made possible. Here, the energy supply of the measurement system must be provided usually by batteries or accumulators. The data transfer to a fixed evaluation station takes place as standard via infrared transmitters and receivers, and increasingly also via radio.
However, the supply by means of battery or accumulator is usually a limiting variable, since the assurance of the energy supply thus leads to additional maintenance and supervision effort. The existing contactless inductive energy transfer devices, which primarily enable an energy supply without galvanic contacts or battery, result in considerable interference with the structure of the rotating elements. The charging station is normally located outside the machine tool, or the application in question must be removed from the machine tool in order to change the battery. In addition, the energy supply in the case of sensor systems or possibly also actively operating, actuator systems generally constitutes a limitation. As a result, and due to the extremely harsh environment in the working area of machine tools, the equipping of tools known per se with additional intelligence is not successful in principle.
In view of this there is a need for tool monitoring systems that can operate with machine tools without external energy supply.